Arm chair



FIG. 1 is a top view of an arm chair showing my new design;

FIG. 2 is a left side view, the right side being a mirror image thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a front view thereof; and,

FIG. 5 is a bottom view thereof. 

The ornamental design for an arm chair, as shown and described. 